How to prevent invalid characters from being typed into input fields

Question

Onkeydown, I run the following JavaScript:

function ThisOnKeyDown(el) {
   if (el.title == \'textonly\') {
       !(/^[A-Za-zÑñ-\\s]*$/i).test(e         


        

Answer 1

i found this solution in: http://help.dottoro.com/ljlkwans.php

works as intended.

<script type="text/javascript">
    function FilterInput (event) {
        var keyCode = ('which' in event) ? event.which : event.keyCode;

        isNumeric = (keyCode >= 48 /* KeyboardEvent.DOM_VK_0 */ && keyCode <= 57 /* KeyboardEvent.DOM_VK_9 */) ||
                    (keyCode >= 96 /* KeyboardEvent.DOM_VK_NUMPAD0 */ && keyCode <= 105 /* KeyboardEvent.DOM_VK_NUMPAD9 */);
        modifiers = (event.altKey || event.ctrlKey || event.shiftKey);
        return !isNumeric || modifiers;
    }
</script>

< body>
The following text field does not accept numeric input:
<input type="text" onkeydown="return FilterInput (event)" />< /body>

it allows text and !"#$%& but you can adjust it adding these to the validationto only allow numbers by removing the ! in the return